Mass Balance of Svalbard Glaciers
We are currently developing a spatially distributed numerical model that can be used to calculate the mass balance of Svalbard glaciers and ice caps in the past, and will be used to predict their changing mass balances and contributions to sea level change in the future. We are running the model for the glacier Midre Lovénbreen, near Ny-Ålesund, where we are able to validate it against past mass balance measurements. A novel component of the model is its ability to calculate firnification (the gradual metamorphosis and densification of snow to firn), superimposed ice formation (refreezing of water above the previous summer’s surface) and internal accumulation (refreezing of percolating water and water held by capillary forces below the previous summer’s surface). Whereas superimposed ice formation is accounted for in mass balance measurements (although not necessarily quantified separately from snow accumulation), internal accumulation is not accounted for and yet previous work on other glaciers has suggested it may account for up to 65% of winter accumulation. We plan to use a combination of snow/firn/ice core and radar measurements on Midre Lovénbreen to quantify the spatial variations in firnification, superimposed ice formation and internal accumulation across the glacier. These will be used to help validate the output from the numerical model, before we extrapolate the calculations to other ice masses across the archipelago.